Effects of Neoadjuvant Chemoradiotherapy on Pathological TNM Stage and Their Prognostic Significance for Surgicallytreated Esophageal Squamous Cell Carcinoma

Background/aim The TNM staging system for esophageal cancer is designed to predict survival based on pathological stage in patients who have been treated with surgery alone. However, pathological stage can vary considerably after neoadjuvant therapy due to tumor responses. Patients and methods We reviewed 110 patients with esophageal squamous cell carcinoma (ESCC) who underwent neoadjuvant chemoradiotherapy (nCRT) followed by surgery, and investigated the effects of nCRT on TNM stage and its prognostic significance. Results A comparison of pre-treatment clinical and pathological stages (cStage and ypStage, respectively) resulted in 75 (68%) of the patients being down-staged. Good responders (over two-thirds of the primary tumor reduced by nCRT) comprised 100%, 83%, 69%, 52% and 50% of patients with ypStages 0, I, II, III and IV, respectively (p=0.001). In addition, 62 (83%) and 20 (57%) of patients with and without down-staged tumors, respectively, were pathological good responders (p=0.004). We found that cStage did not significantly correlate with survival, whereas univariate analysis significantly associated ypStages III/IV (p=0.003) and down-staged tumors (p=0.04) with overall survival (OS). Multivariate analysis selected ypStage III/IV (HR=3.26; 95% CI=1.52-6.99; p=0.002) and no down-staging (HR=2.06; 95%CI=1.16-3.64, p=0.01) as independent covariates for OS. Conclusion nCRT could lead to down-staged ESCC tumors for many patients and a good prognosis. The correlation between ypStage and pathological response to nCRT indicated that ypStage could stratify survival and serve as a prognostic predictor after trimodal therapy.